A stator of a molded motor is manufactured by winding a coil around a stator core and integrally molding the coil and the stator core using a molding resin. In recent years, reduction of the amount of use of the molding resin is required in order to reduce manufacturing cost.
Accordingly, a technique is proposed in which a resin thermally cured in a runner of a mold in previous molding is placed in a cavity of the mold in next molding so that the resin is integrated with a molding resin injected into the cavity (see, for example, Patent Reference 1).
Moreover, another technique is proposed in which a ring shaped groove is provided at an axial end surface of a stator so as to reduce the amount of use of a molding resin by an amount corresponding to a volume of the groove (see, for example, Patent Reference 2).